DDC Top & Pump Performance Comparison (Petra's, Radiical, Alphacool, etc.)

[situman]

I'm interested in a modular full cover gpu waterblock. Those things just look awesome, especially the ones from EK but I just can't justify buying a new waterblock everytime there's a new vidcard out there.

[el rolio]

hey petra, as the owner of the first retail block, a RECORD setting (hahah) order placer 3 tuesdays in a row, and a loyyal customer.... i have requests:

it is true that your top does create some noise. i know you folks are looking into the different internal machining to possible lower that, as well as get improved performance, but yea, its important to me. i'm keeping my first top for its significance, just like i would never sell my storm block. but i think next tiem i go into my loop im swapping in the alphacool top in the meantime to confirm/debunk my feeling that the pump is louder with the top (other things changed in the loop, but that shouldnt be it)

take ya time tho, you know that i'll be in the ps3-esque line for your r2 top

[kimandsally]

Since you're in the UK, I went ahead and forwarded your e-mail to Quoc.

AFAIK, our resellers in the UK have sold out of our DDCT-01 tops (you can still order from us directly, though). Additionally, we *just* sold the last of our first production run (so, yes, there are now 197 of them floating around out there...incase you're wondering where the other 3 went (5, if you count the two prototypes), well, I have them ). The only store in the US that still has some tops and combos left would be Sidewinder.

That aside, we worked out some stuff with friends of ours at a different machine shop that's just down the street and, hopefully, we'll have our second run done and ready to ship sometime next week. I have yet to see a sample top from them but they should be identical to the current ones (aside from "Petra'sTech" being written on the top instead of "PetrasTechShop.com" (done to make the tops a little more reseller-friendly) and there being fewer visible tooling marks due to the use of more appropriate bits). The cool thing about working with this shop is that they have much larger production capacity and excellent machining capabilities (their QC is also lightyears ahead of what what we had before)... look for some cool stuff in the future, as a result.

In other news, I'm am planning on completely redesigning the DDC tops in the not-so-distant future...but it'll be quite a while (planning on making them cleaner looking, a bit smaller/less bulky, implementing a straight outlet, completely redesigning the internals (I have a few tricks I'd like to try out to see how much more performance I can squeeze outta the DDC), and working in some sort of 3.5" bay mount capability). I'll likely move on to waterblocks and stuff in the future as well... in the short-term, however, I may be occupied with cooking up a GPU block for DragonOrta's X1650XT (if he can manage to volt-mod the GPU, that is). Though, I also have some interesting ideas that I'd like to experiment with involving TECs and stuff, but that'll have to wait.

Anyway, yeah, that's all from my not-so-secret lab for now...

Thanks

Really pleased I found this thread, I love to see compassion for quality, to me the quality is everything so I'll be patient and wait until you have some or Quoc gets in contact with me.

Good luck to all your future projects, I await to see what's coming next.

[zhangmaster12]

im getting that delrin top petra

[h-hop]

hi,

plan to get DDCT-01 Specifications (w/18W DDC-2), but does it operate in 30 ~ 32 dBA as DDC-2 or getting more louder?

[Lu523]

I have read most of this thread. From looking at the charts and all I have a question. I am using a 50Z. Would the pump with Petra's top be a choice?
My loop is the 50Z, BIP II rad, Swiftech Storm cpu block, and MCW60 vga block. System specs are in sig. I have the cpu running at 3330 @ 1.25 vcore and the gpu @ 644Mhz. I know have just added the gpu block. I know temps are going to be higher with it in the loop. I would just like to know if the pump will help more than a new rad.

I forgot to mention temps. CoreTemp shows 40/39 idle and 52 load. That is with 2 Yate fans on high.

[Graystar]

I would just like to know if the pump will help more than a new rad.

Unless you have a pump designed for table-top fountains (which you don't,) bigger/better rad is always the way to go.

If you were to change the pump, my guess is that you would see no improvement.

[Quazi]

Go with the pump upgrade to the DDC-2 w\Petras Top. A Storm requires all the head pressure it can get to perform like it should. Your 50z has a Maximum Head of 11.9ft. The DDC-2 w\Petras Top has a Maximum Head of 23.3ft. This pump also has substancially better flow rates than your 50z and your MCW60 VGA block will probably benefit better from that. So overall, I believe you will get better results by replacing your pump rather than replacing your rad.

Now the main reason I said what I did is because you do have a Storm in the loop. If your cpu block were of the high flow rate kind, then I would have advised replacing the rad. But in order to get the most out of any water cooling setup, certain components dictate the use of other components. And the Storm is the dictator in your setup just as it is in anyones setup. And it needs a pump with a substancial head pressure to perform at its best. Plus the fact that the DDC-2 w\Petras Top has better flow rates than your 50z, it is a no brainer. Imo, replacing your 50z with the DDC-2 w\Petras Top is the way to go here.

[Graystar]

Go with the pump upgrade to the DDC-2 w\Petras Top. A Storm requires all the head pressure it can get to perform like it should. Your 50z has a Maximum Head of 11.9ft. The DDC-2 w\Petras Top has a Maximum Head of 23.3ft. This pump also has substancially better flow rates than your 50z and your MCW60 VGA block will probably benefit better from that. So overall, I believe you will get better results by replacing your pump rather than replacing your rad.

Now the main reason I said what I did is because you do have a Storm in the loop. If your cpu block were of the high flow rate kind, then I would have advised replacing the rad. But in order to get the most out of any water cooling setup, certain components dictate the use of other components. And the Storm is the dictator in your setup just as it is in anyones setup. And it needs a pump with a substancial head pressure to perform at its best. Plus the fact that the DDC-2 w\Petras Top has better flow rates than your 50z, it is a no brainer. Imo, replacing your 50z with the DDC-2 w\Petras Top is the way to go here.

I can say with confidence that this advice is absolutely wrong.

The 50Z should be able to move more than 1 GPM through the system as described. Once flow reaches 0.75 to 1 GPM further increases will not produce measurable improvements.

An additional radiator, on the other hand, could drop temps by 2C. The radiator is definitely the way to go.

[Petra]

Go with the pump upgrade to the DDC-2 w\Petras Top. A Storm requires all the head pressure it can get to perform like it should. Your 50z has a Maximum Head of 11.9ft. The DDC-2 w\Petras Top has a Maximum Head of 23.3ft. This pump also has substancially better flow rates than your 50z and your MCW60 VGA block will probably benefit better from that. So overall, I believe you will get better results by replacing your pump rather than replacing your rad.

Now the main reason I said what I did is because you do have a Storm in the loop. If your cpu block were of the high flow rate kind, then I would have advised replacing the rad. But in order to get the most out of any water cooling setup, certain components dictate the use of other components. And the Storm is the dictator in your setup just as it is in anyones setup. And it needs a pump with a substancial head pressure to perform at its best. Plus the fact that the DDC-2 w\Petras Top has better flow rates than your 50z, it is a no brainer. Imo, replacing your 50z with the DDC-2 w\Petras Top is the way to go here.

Actually, max head was 18.68' at 12V... 23.3' was at 13.8V.

That aside, I'm afraid that I'd have to agree with Graystar on this one. He'd only be gaining about 0.3GPM through his loop (likely a tiny bit more) but at the cost of additional heat dump. Power consumption and heat dump are things to keep in mind--9W vs. 18W, in this case (I'm simplifying things here (assuming 0% efficiency & max flow), so nobody go after me about pump efficiency and actual waste heat production). Now, if he were coming from a pump with more heat dump and less flow at a given head pressure, then I'd say go for it... in this case, though, I'd recommend going for the new radiator. PA120.3, anyone?

[Lu523]

Thanks for the response everyone. I was leaning torward a better rad. Main thing I am trying to do is get the temps down with the least amount of cash. If that means a PA120.3 then so be it.

[Fairydust]

Alex are you gonna retest your top with the new revision DDCs that have a smaller impeller inlet?

[Petra]

Alex are you gonna retest your top with the new revision DDCs that have a smaller impeller inlet?

New revision? I haven't seen any of those yet... Pics/specs/detailed internal dimensions?

[Fairydust]

Only pics i could find. Dunno if the impeller inlet is used on both DDC and DDC+, but the DDC+ i put in a system this weekend also had a blue impeller.

Seems like they also have a new pcb (dead pump issue fixed?).

[kemist]

Only pics i could find. Dunno if the impeller inlet is used on both DDC and DDC+, but the DDC+ i put in a system this weekend also had a blue impeller.

Seems like they also have a new pcb (dead pump issue fixed?).

Do you know what size the orange impeller opening is? I thought it was smaller like the blue one, not large like the black. Anyone know?

[Fairydust]

The orange/brown impeller opening looks to be the same size as the black one.

[Radical_53]

On the normal DDCs, the impeller opening was a little larger on the DDC+. At least the two pumps of both types I measured Not by much, but a little larger...

[Petra]

Well, I'm getting conflicting information from one of our UK resellers... so I'm just gonna get in touch with Laing and find out what's going on. Worst comes to worst, I'll have one of the blue impellered pumps shipped to me from the UK to verify compatibility and see if there's a performance difference.

[serialk11r]

New DDCs? I just got mine! I hope your next version of your top is coming along well.

[Lu523]

Actually, max head was 18.68' at 12V... 23.3' was at 13.8V.

That aside, I'm afraid that I'd have to agree with Graystar on this one. He'd only be gaining about 0.3GPM through his loop (likely a tiny bit more) but at the cost of additional heat dump. Power consumption and heat dump are things to keep in mind--9W vs. 18W, in this case (I'm simplifying things here (assuming 0% efficiency & max flow), so nobody go after me about pump efficiency and actual waste heat production). Now, if he were coming from a pump with more heat dump and less flow at a given head pressure, then I'd say go for it... in this case, though, I'd recommend going for the new radiator. PA120.3, anyone?

I went an ordered the PA120.3. Will post back with results.

[eXa]

uppdates on the ddc? this is interresting.
Petra, could u pm me when\if u get some nice new info i can put in the ddc sticky?

[Quazi]

Well, I am sorry. Of all the information I have been reading here, I was under the impression that highly restrictive water blocks such as the Storm requires a pump that has very good head pressures. And that performance gains from using a pump with better head pressures would equate to substancial cooling improvement as far as temps go.

So am I wrong? Do Storms not require pumps that provide higher head pressures to perform at its' best? I don't post often. And I only post when I feel like I know what I am talking about. This was one time I was confident that I was knew what I was talking about. I hate misinformation. Again, my apologies. I hope the rad upgrade works the way you expect it to m8.

[Graystar]

Well, I am sorry. Of all the information I have been reading here, I was under the impression that highly restrictive water blocks such as the Storm requires a pump that has very good head pressures. And that performance gains from using a pump with better head pressures would equate to substancial cooling improvement as far as temps go.

So am I wrong? Do Storms not require pumps that provide higher head pressures to perform at its' best? I don't post often. And I only post when I feel like I know what I am talking about. This was one time I was confident that I was knew what I was talking about. I hate misinformation. Again, my apologies. I hope the rad upgrade works the way you expect it to m8.

To understand this you have to first understand 1. how flow affects temps, 2. what is the correct flow rate, and 3. what kind of flow rates we get now.

1. how does flow affect temps?
A change in flow affects temperature by changing the average temperature of the waterblock. Water enters the block at one temperature and leaves at another. The average of those two temps is the average temp of the block (well, little more complicated than that but really, that’s good enough.) As flow rate increases, the difference in temperature between water in and water out gets smaller. This drop in average temp *provides the opportunity* to reduce the temperature of the CPU (it aint written in stone that it will definitely drop.)

2. what is the correct flow rate?
Well, obviously, the trend described above can continue for infinity. So you can’t really say correct...only good enough. However, for a 100-watt heat load a flow of 1 GPM will give you a difference between water-in/water-out of only 0.378 C. That means that doubling your flow to 2 GPM could potentially improve temps by a mere 0.0945 C (half of half of 0.378 C is the way it works out.)

3. what kind of flow rates do we get now?
Lee Garbutt of SystemCooling.com performed tests on DDCs and D5s and found that they provided about 1.5 GPM in your basic restrictive loop.

Well, those are the facts. The rest I’m just making up as I go along

Seeing how little there is to be gained from relatively large increases in flow, my conclusion is that you should have enough flow for a delta of 0.5 C between water in the block and water out of the block. That will get you very close to the best cooling possible, and I believe that if you increase flow to go any lower than that then you’re really just throwing heat at a problem you can never solve.

From this comes my basic rule for flow rate of starting with 0.5 GPM and adding 0.5 GPM for every 100 watts of expected heat. So if you’re cooling a OCed single or efficient dual, then 1 GPM is good enough. If you have an OCed quad core and two hot GPUs in your loop, then you need 2, possibly 2.5 GPM to get a delta of 0.5 C.

Lee Garbutt’s tests shows that your typical water cooler is just fine with a good Laing pump. It’s only the really hot setups that need more flow. But really, a flow of 1.5 GPM with a 300-watt heat load only gives a delta of 0.76 C. So yes, it’s more than 0.5 C, but only a tiny bit more. The hot setups also suffer higher head loss from having more components. However, I'd like to see more tests with the DDC-2 in such setups before declaring that everyone needs two DDC-2 with aftermarket tops in their loops.

[Quazi]

Thank you very much for taking the time to explain it. And you explained it in such a way that my pea sized brain actually can grasp what you are saying. I am going to copy and paste your post to notepad. Some fantastic information. The technical aspect of water cooling continues to blow me away.

There are some m8s around here running DDC-2's back to back. Some say it is for redundancy. But some have mentioned trying to increase flow through the Storm. From your post, that isn't much of a performance increase to warrant another $100 purchase. I never thought anyone would spend $100 for less that .5C temperature improvement.

I can definitely see where a radiator upgrade would stand a better chance of improving temps rather than a pump upgrade in this m8s case.

Thanks again Graystar! You have really been helpful in clearing up a huge misunderstanding for myself. This information is so clearly stated, it should be required reading for anyone, especially new m8s looking at getting into water cooling for the first time. I know it would have saved me $100 cause I would have continued to use my Laing D-4 with its 10ft of Head & 317 GPH of flow when I decided to get a Storm.

[Fairydust]

Well, I'm getting conflicting information from one of our UK resellers... so I'm just gonna get in touch with Laing and find out what's going on. Worst comes to worst, I'll have one of the blue impellered pumps shipped to me from the UK to verify compatibility and see if there's a performance difference.

Seems like normal and plus version now share the exact same layout in the new revision, there is even mod to change normal to plus version.